Algol

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Beta Persei A/B/C
Perseus constellation map.svg
Locator Dot2.gif

The reid dot shaws the location o Algol in Perseus.
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Richt ascension 03h 08m 10.1315s[1]
Declination +40° 57′ 20.332″[1]
Apparent magnitude (V) 2.12[1]
Characteristics
Spectral type B8V (A)[1] /K0IV (B)[2] /A5V (C)
U−B colour index −0.37
B−V colour index −0.05
Variable type Eclipsin binary
Astrometry
Radial velocity (Rv) 3.7 km/s
Proper motion (μ) RA: 2.39 mas/yr
Dec.: −1.44 mas/yr
Parallax (π) 35.14 ± 0.90 mas
Distance 93 ± 2 ly
(28.5 ± 0.7 pc)
Absolute magnitude (MV) −0.15
Details
Mass 3.59/0.79/1.67 M
Radius 4.13[3]/3.0/0.9 R
Luminosity 98/3.4/4.1 L
Temperatur 9,200[3]/4,500/8,500 K
Metallicity Nae available
Rotation 65 km/s
Age < 3×108 years
Ither designations
Algol, Gorgona, Gorgonea Prima, Demon Starn, El Ghoul, β Persei, β Per, Beta Per, 26 Persei, BD+40°673, FK5 111, GC 3733, HD 19356, HIP 14576, HR 936, PPM 46127, SAO 45864.

Algol (Beta Per, β Persei, β Per), kent colloquially as the Demon Starn, is a bricht starn in the constellation Perseus. It is ane o the best kent eclipsin binaries, the first such starn tae be discovered, an an aa ane o the first (non-nova) variable starns tae be discovered. Algol is actually a three-starn seestem (Beta Persei A, B, an C) in which the lairge an bricht primary Beta Persei A is regularly eclipsed bi the dimmer Beta Persei B. Thus, Algol's magnitude is usually near-constant at 2.1, but regularly dips tae 3.4 every twa days, 20 oors an 49 minutes durin the roughly 10-oor lang partial eclipses. Thare is an aa a seicontary eclipse (the "seicont minimum") when the brichter starn occults the fainter seicontary. This seicontary eclipse can anly be detectit photoelectrically.[4] Algol gies its name tae its class o eclipsin variable, kent as Algol variables.

References[eedit | eedit soorce]

  1. 1.0 1.1 1.2 1.3 Database entry for Algol A, SIMBAD. Accessed online February 9, 2008.
  2. Database entry for Algol B, SIMBAD. Accessed online February 9, 2008.
  3. 3.0 3.1 Rhee, Joseph H. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal 660 (2): 1556–1571, arXiv:astro-ph/0609555, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912 
  4. Beta Persei, American Association of Variable Star Observers. http://web.archive.org/web/20030705115540/http://www.aavso.org/vstar/vsots/0199.shtml[deid airtin]